I posted this a while ago but thought it was worth re-posting. Last year I went to a trade show and saw a lot of activity around a company that places a skin over the existing bathtub and walls. They claim to be in and out in one day. The product looks quite nice and clean but plain. There are some applications in which they might work. If your tub and tile are sound, without any missing grout, leaks, or mold. You have a new shower mixer control or have access to the back of the shower for replacement when it no longer functions, then maybe. Otherwise, it is my opinion these are a bad idea.
Most bathrooms were built using either drywall or more recently aquaboard, neither of these are rated for wet areas. The starch contained in these materials are a food source for mold. Unless you seal the grout and reseal it on an ongoing basis the grout becomes a vehicle to water migration into the wallboard. This creates a nice warm, moist environment for mold to flourish. Covering this up does not fix the problem, it only hides it. It is the equivalent of putting a band aid over a wound without cleaning it out first.
The next issue that I have with these systems, in most cases, they do not address the plumbing. If you have 10, 20 or 30-year-old mixer valve and taps, they will fail. Now you need to call the company back to remove the skin, so you can give the plumber access to repair or replace the problem. Then you must call them again to re-install it once the repairs are complete.
What we do
Let me contrast that with what we do. We begin by removing the walls around the bathtub and the bathtub itself. Then we inspect the walls for any mold issues and repair, as necessary. We always replace the plumbing with new top-quality mixer valve and shower head. We install the new bathtub, then create a complete waterproof envelope, using materials that are impervious to mold. Once the basics are done properly, we install beautiful new tile including niches, shelves, or highlight accents and finish it off with a top-quality self-sealing grout. The whole process takes about 3 days.
So, you can hide the problem in one day or have a completely new bathroom in about 3 days.